Can ends which are seamed to the outermost edge portions of cylindrical container bodies to form a beverage container are typically manufactured from metal stock, such as aluminum or steel sheet. First, a circular blank is cut from the sheet and formed between upper and lower reciprocating die assemblies in end-making machines (which are well known in the art) into the basic end configuration or "shell". After curling (by one of several well known techniques), the shell may be considered finished for some applications, but typically is further processed to include an easy-opening device, such as a ring pull tab or stay-on-tab. The term "end" will be used herein to refer to a shell, a finished end with an easy-opening device, and intermediate products in different stages of manufacture in between. Ends are sometimes called "lids".
The ends typically have a center panel of circular shape and a formed peripheral edge consisting of a countersink radius lip extending below the center panel and a seaming panel extending upwardly from the center panel. The seaming panel terminates in a curved peripheral flange located above the center panel and it is this flange which will be later seamed to a flange formed in the open end of the cylindrical container body.
It is customary in automated assembly facilities to utilize preformed and pre-stacked can ends. These nested stacks of can ends are usually provided in pre-packaged form wherein an entire package is introduced into a generally tubular conveyor or conduit for feeding to a processing machine where they are attached to the container bodies.
Stripping and removal of packaging material from the nested stacks of can ends may sometimes cause various of the ends at or near the end of the stack to be dislodged or flipped within the stack and therefore lie in reverse orientation relative to the remaining ends in the stack and no longer nested. Obviously, an end placed in reverse orientation is no longer properly oriented and may not be accommodated by processing equipment. Indeed, such reversed ends, if fed into the processing equipment, may lead to a malfunction of such equipment.
Systems for detecting and ejecting reversed ends from a moving stack of otherwise similarly aligned and nested can ends are known. However, these systems generally rely upon relatively complicated mechanical systems or optical detection apparatus and electronic circuitry for producing a control signal to actuate complicated mechanical ejectors.
It is accordingly one object of the present invention to detect a reversed can end and eject same from a moving stack or line of can ends which are properly oriented prior to the point of introduction of the can ends into processing equipment.
Another object is to remove such reversed can ends utilizing a system which may be readily inserted into an existing conveyor line with only minimal if any modification thereto.
Another object is to provide a reversed end ejection system which is relatively simple and inexpensive in its design and manufacture but capable of reliable operation.